Fine structural studies of motor nerve terminals in transforming claw closer (Cll) muscles will be made. Changes in terminal density and diameter will be sought. The anatomical structure and electrical properties of excitatory motor neurons to Cll will be analyzed for pincer and snapper claws to determine what modifications may occur during transformation. Possible influences of transforming muscle on motor nerve terminals will be sought by experimental means. Why are changing properties of nerve and muscle linked during transformation?